Introduce printers for Node and Position for ease of developing GTest test files

Source/core/editing/VisibleSelectionTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/editing/VisibleSelection.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/Range.h"
 #include "core/dom/Text.h"
 #include "core/html/HTMLElement.h"
+#include "core/testing/CoreTestHelpers.h"
 #include "core/testing/DummyPageHolder.h"
 #include <gtest/gtest.h>
 
 #define LOREM_IPSUM \
     "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor " \
     "incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud " \
     "exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure " \
     "dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur." \
     "Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt " \
     "mollit anim id est laborum."
@@ skipping 216 matching lines @@
         selection.expandUsingGranularity(WordGranularity);
 
         RefPtrWillBeRawPtr<Range> range = selection.firstRange();
         EXPECT_EQ(0, range->startOffset());
         EXPECT_EQ(11, range->endOffset());
         EXPECT_EQ("Lorem ipsum", range->text());
     }
 }
 
 } // namespace blink